Plastic cases for beverage bottles are commonly rectangular and have side walls and a floor which is a latticework of floor support ribs. The floor is made this way to minimize the weight of the case, to minimize any accumulation of debris in the case, and to make it easier to wash out. The inner space in the case is divided in one of several possible ways into bottle receiving compartments suited to the bottle size to be accepted by it.
In one type of case the inner space is divided into compartments by a number of columns which extend vertically from the floor. The columns have a roughly cross-shaped cross-section and are placed so that they each extend vertically in the space between a group of four bottles to keep the bottles spaced sufficiently that they do not break when they are jostled. In some cases of this type, the columns are slotted in at least one direction, parallel with the side walls to form a group of two or four facing double-walled pillars. This permits bottles to be accepted together with a hand carrier, such as a "six-pack" carrier of cardboard. Such a case is described, for example, in U.S. Pat. No. 4,071,162, Steinlein et al, which is assigned to the same assignee as that of the rights to the present invention. One or more walls of the carrier are slid into aligned slots of the columns. The columns enter the carrier through openings in the bottom of the carrier. The columns thereby supplement the protection against breakage which is afforded by the carrier alone. When the bottles are returned empty without the carrier, they can be returned alone to the case and are then similarly protected by the pillars. This protection is very important, since inadequately protected empty bottles can easily develop hair-line fractures which render them unsuitable for refilling, but which are very difficult to reliably detect.
A persistent problem with cases of the type described above which have at least one slotted column has been that with certain configurations of the floor, particularly a cartesian or rectangular floor lattice, the pillars of a column move together after the molding of the case, thereby impairing the loading of a carrier into the case due to insufficient slot clearance for readily accepting the carrier wall in the slot. This reduced slot clearance is a result of warping which occurs upon cooling of the case after unmolding. Yet, for material economy and other structural reasons it is often preferred to use, for instance, a floor configuration of the type described above.